Sensitivity of quantum-dot semiconductor lasers to optical feedback

The sensitivity of quantum-dot semiconductor lasers to optical feedback is analyzed with a Lang–Kobayashi approach applied to a standard quantum-dot laser model. The carriers are injected into a quantum well and are captured by, or escape from, the quantum dots through either carrier–carrier or phonon–carrier interaction. Because of Pauli blocking, the capture rate into the dots depends on the carrier occupancy level in the dots. Here we show that different carrier capture dynamics lead to a strong modification of the damping of the relaxation oscillations. Regions of increased damping display reduced sensitivity to optical feedback even for a relatively large α factor.